thanks for all your help everyone it's been interesting reading.
I guess i'll be simply going for the single sub set up, but if Seyles comes back on or anyone else knows what he was talking about in message 2 and the Isobaric set up, i believe it's two speakers run face to face but a laymans term breakdown would be interesting.
In regards to RMS power, i still can't understand why manufacturers still quote other "mickey mouse terminology" (peak, mpo, pmpo, etc)apart from making a sh!te product sound more impressive in a brochure. If your dealer can't quote an RMS figure then go and buy something else, or you'll only be disappointed.
If anyone wants a fair product for fair money, check out the mutant range at halfords. or try
www.mutant.uk.com.